The present disclosure relates to a search apparatus, a search method, and a program.
In recent years, the possibility to search for various information, for example, using the Internet, has increased. For example, searches for transfer information of transportation facilities, information of a route to a destination, and the like are being routinely performed. Further, searches for shop information at a street or information of a ticket or a coupon using a portable device such as a portable telephone or a personal digital assistant are being routinely performed. Thus, recently, an information search chance has rapidly increased. Further, as users of information search services increase, an infrastructure of an information search system has been provided. As a result, recently, various information can be instantly searched, for example, using portable devices.
Assuming use of a portable device with which it is difficult to input search conditions, speech search service in which search conditions can be input through speech has been devised. Further, information search service in which a search condition can be input with a format of a natural sentence, “Show me a cheap sushi restaurant in Ginza,” has also been devised. As a result, the search condition can be rapidly and simply input, thus greatly improving usability. However, in a number of information search services, even when subjective representations “cheap” and “good” are contained in a search condition, only information containing wordings “cheap” and “good” is extracted.
For example, even when search is performed using a natural sentence, “Show me a cheap sushi restaurant in Ginza,” as a search condition, only sushi restaurant information containing the keyword “cheap” is extracted and information on some low-priced sushi restaurants may not necessarily be extracted. Thereby, a user desiring to obtain information on cheap sushi restaurants has to perform a search using a search condition containing a price range they consider cheap or has to confirm extracted information of sushi restaurants one by one and find the cheap sushi restaurants. As a solution to such a problem, a method in which a database with subjective representations associated with numerical ranges is prepared in advance and a subjective representation contained in a natural sentence input as a search condition is automatically converted into a numerical range to perform search is disclosed in Japanese Patent Laid-open Publication No. 2002-24212.